//
// (C) Copyright 2009 Irantha Suwandarathna (irantha@gmail.com)
// All rights reserved.
//

/* Copyright (c) 1995-2000, The Hypersonic SQL Group.
 * All rights reserved.
 *
 * Redistribution and use _in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions _in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer _in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the Hypersonic SQL Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE HYPERSONIC SQL GROUP,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * on behalf of the Hypersonic SQL Group.
 *
 *
 * For work added by the HSQL Development Group:
 *
 * Copyright (c) 2001-2008, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use _in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions _in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer _in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


using System;
using EffiProz.Core.RowIO;
using EffiProz.Core.Indexes;
using EffiProz.Core.Persist;
using EffiProz.Core.Lib;
using EffiProz.Core;

namespace EffiProz.Core.Indexes
{

    // fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)
    // fredt@users 20020920 - path 1.7.1 - refactoring to cut mamory footprint
    // fredt@users 20021205 - path 1.7.2 - enhancements
    // fredt@users 20021215 - doc 1.7.2 - javadoc comments

    /**
     *  The parent for all AVL node implementations, features factory methods for
     *  its subclasses. Subclasses of Node vary _in the way they hold
     *  references to other Nodes _in the AVL tree, or to their RowAVL data.<br>
     *
     *  nNext links the Node objects belonging to different indexes for each
     *  table row. It is used solely by RowAVL to locate the node belonging to a
     *  particular index.
     *
     *
     * @author Thomas Mueller (Hypersonic SQL Group)
     * @version 1.7.2
     * @since Hypersonic SQL
     */
    public abstract class NodeAVL : CachedObject
    {

        public const int NO_POS = RowAVLDisk.NO_POS;
        public int iBalance;    // currently, -2 means 'deleted'
        public NodeAVL nNext;       // node of next index (nNext==null || nNext.iId=iId+1)


        /**
         *  This method unlinks the Node from the other Nodes _in the same Index
         *  and from the RowAVL.
         *
         *  It must keep the links between the Nodes _in different Indexes.
         */
        public abstract void delete();

        public virtual bool isMemory()
        {
            return true;
        }

        /**
        *  File offset of Node. Used with CachedRow objects only
        */
        abstract public int getPos();
        

        /**
         *  Return the RowAVL Object that is linked to this Node.
         */
        public abstract Row getRow(PersistentStore store);



        /**
         *  Getters and setters for AVL index operations.
         */
        public abstract bool isLeft(NodeAVL node);

        public abstract bool isRight(NodeAVL node);

        public abstract NodeAVL getLeft(PersistentStore store);

        public abstract NodeAVL setLeft(PersistentStore store, NodeAVL n);

        public abstract NodeAVL getRight(PersistentStore store);

        public abstract NodeAVL setRight(PersistentStore store, NodeAVL n);

        public abstract NodeAVL getParent(PersistentStore store);

        public abstract NodeAVL setParent(PersistentStore store, NodeAVL n);

        public abstract int getBalance(PersistentStore store);


        public abstract NodeAVL setBalance(PersistentStore store, int b);

        public abstract bool isRoot(PersistentStore store);

        public abstract bool isFromLeft(PersistentStore store);

        /**
         *  Returns the database table data for this Node
         *
         */
        public abstract Object[] getData(PersistentStore store);

        public abstract NodeAVL set(PersistentStore store, bool isLeft, NodeAVL n);

        public abstract void replace(PersistentStore store, Index index, NodeAVL n);

        public abstract bool Equals(NodeAVL n);


        public void updateAccessCount(int count) { }

        public int getAccessCount()
        {
            return 0;
        }

        public void setStorageSize(int size) { }

        public int getStorageSize()
        {
            return 0;
        }

        public void setPos(int pos) { }

        public virtual bool hasChanged()
        {
            return false;
        }

        public virtual bool isKeepInMemory()
        {
            return false;
        }


        public virtual bool keepInMemory(bool keep)
        {
            return true;
        }

        public virtual  bool isInMemory()
        {
            return false;
        }

        abstract public void setInMemory(bool _in);

        public virtual void restore() { }

        public virtual void destroy() { }

        public virtual int getRealSize(RowOutputInterface _out)
        {
            return 0;
        }

        abstract public void write(RowOutputInterface _out);

        public virtual void write(RowOutputInterface _out, IntLookup lookup) { }


    }
}
